Yes, there is a big viewing hill-type place around turn five. If you look on the map, move the turn one indicator to the inside of the track. Now connect the dots of 1, 10, 11, and then follow the track all the way around to 5,4, and back to 1. That whole area it makes is basically one big open area. And this is what you were probably seeing:

It is actually a great place to watch from, hence the crowd. You get the cars coming into heaving breaking off the straight into Turn 4, followed by turn 5 which is neat because it's still uphill and then also diving back downhill into another relatively sharp righthander

There is also a fun to watch and on the other side, where the cars are climbing uphill again under the walkover:

I know you mentioned not wanting to change places too much, but if you haven't ever been to Mid-Ohio, you have to take in Thunder Valley. To me, the sounds of racing don't get much better than there. It's just like it sounds, the engine sounds have nowhere else to go and just amplify in the small valley there. Incredible! Make sure you are on the inside of the track for that. It's also pretty shady, which can be nice at an August race. Also you can't see in the picture, but when the cars go into turn 11, they are somewhat light on their feet because the peak of the uphill, so I do enjoy watching the turn there as well (from thunder valley, the view is better IMO)

Anything else, just let me know